Moses steps out of the city, spreads his hands in prayer to God, and the devastating storm comes to a sudden and miraculous halt. The heavy elements of the plague immediately stop pouring down to the earth [רש״י, אבן עזרא, רשב״ם, שד״ל]. A surprising detail emerges as rain is suddenly noted as stopping, even though it was not previously mentioned during the plague of hail. There are a few ways to understand this addition. Since rain in Egypt is naturally a rare and wondrous event, the text highlights that this unusual occurrence also ceased [ביאור יש״ר]. Alternatively, this detail points to a suspension of natural processes. Normally, when freezing hail stops, the remaining moisture in the air thaws into a heavy downpour. The miracle was that this secondary downpour never happened; everything ended instantly [רש ר הירש, אלשיך]. Another perspective connects the rain to the fire flashing within the hail. The intense heat and lightning melted the hard atmospheric vapors into water. Once Moses prayed and the supernatural fire vanished, the melting process ended, preventing any rain from falling [הכתב והקבלה, נתינה לגר].
A fascinating discussion surrounds exactly how the storm stopped. The primary approach among commentators is that a double miracle occurred. Not only did the clouds stop producing precipitation, but the hail and rain that were already falling were suspended in mid-air, never reaching the ground [רש״י, רבנו בחיי, ברטנורא, צאינה וראינה]. These frozen hailstones remained hanging in the atmosphere for decades, eventually falling on the enemies of the Israelites during the battle of Beth-horon in the days of Joshua, with the remainder destined to fall during the future war of Gog and Magog [רבנו בחיי, הדר זקנים, אלשיך]. Conversely, another viewpoint rejects the idea of a mid-air suspension, arguing that the storm simply stopped at the cloud level. According to this view, if such a massive miracle of floating water had occurred, it would have been stated explicitly [רלב״ג].
The sudden and unnatural end to the plague directly influenced Pharaoh's reaction. Moses had promised that the thunder would cease first, followed by the hail. However, since sound travels slower than falling physical objects, God suspended the falling hail and rain in the air to mislead Pharaoh. As a result, Pharaoh saw the hail and rain stop while he was still hearing the final echoes of the thunder. Believing there was a mismatch between Moses's warning and the actual events, and assuming the storm had simply passed naturally, Pharaoh dismissed God's intervention and continued to sin [מלבי״ם, אלשיך].
Ultimately, this event shows the immense power of prayer. Just as the prayers of the righteous can bring blessed rain and atone for the people, they are equally capable of halting rain and divine wrath, exactly as Moses accomplished in Egypt [בעל הטורים].